We propose a framework for estimation and inference when the model may be misspecified. We rely on a local asymptotic approach where the degree of misspecification is indexed by the sample size. We construct estimators whose mean squared error is minimax in a neighborhood of the reference model,...

We develop a multi-risk SIR model (MR-SIR) where infection, hospitalization and fatality rates vary between groups-in particular between the "young", "the middleaged" and the "old". Our MR-SIR model enables a tractable quantitative analysis of optimal policy similar to those already developed in...